Performance Analysis of a PG6581B Gas Turbine-based Coal-fired Combined Cycle System

The construction and features of a PG6581B gas turbine-based coke-carrying thermal partial-gasification coal-fired combined cycle system are described along with a calculation and analysis of the performance of the PG6581B gas turbine when firing coal gas of medium and low calorific value. The results of the calculation indicate that the output power and efficiency of the PG6581B will somewhat be reduced when firing the above-mentioned coal gas, but the reduction is within an acceptable range. A further analysis has revealed that by lowering the content of non-combustible constituents in coal gas, such as CO_2 and N_2 and by increasing the H_2 content in the combustibles it is possible to enhance gas turbine performance. A preliminary calculation of the combined cycle system shows that the thermal efficiency of the PG6581B gas turbine-based coke-carrying thermal partial-gasification coal-fired combined cycle system can exceed 42%.